A taper hub unit is used in a vehicle having a vehicle body of a frame structure such as a truck, and a bearing device used in the taper hub unit includes an outer ring, an inner ring, a plurality of roller rolling elements, and a cage. The outer ring and the inner ring have two rows of raceway surfaces. The roller rolling elements are disposed in two rows so as to roll in two rows of raceway surfaces (the outer ring and the inner ring). The cage holds the plurality of roller rolling elements in a space interposed between the raceway surface of the outer ring and the raceway surface of the inner ring.
By the way, an outer ring in a bearing device having a plurality of bearing rings has been formed by a plurality of members.
Patent Literature 1 discloses a bearing device in which rolling elements are disposed in two rows. As illustrated in FIG. 16, in a bearing device 901, an outer ring 902 includes a pair of outer ring members 903 and 904 having a single row of groove. The pair of outer ring members 903 and 904 are fixed on an inner circumferential surface of each outer ring member so as not to be separated by an annular resin coupling ring 909.